1. Field
The present disclosure relates to inkjet printing apparatuses driven using piezoelectric and electrohydrodynamic techniques, and methods of driving the inkjet printing apparatuses.
2. Description of the Related Art
An inkjet printing apparatus is a device for printing a predetermined color image by ejecting minute droplets of ink on desired areas of a printing medium example (e.g., printing sheet) by using an inkjet head. Inkjet printing apparatuses have been widely used in various applications, including flat displays (e.g., liquid crystal displays (LCDs)), organic light emitting devices (OLEDs), flexible displays (e.g., E-paper), printed electronics (e.g., metal wirings), and organic thin film transistors (OTFTs). When inkjet printing apparatuses are used in various display fields or printed electronics fields, high-resolution and superprecision printing are of relatively high importance.
Inkjet printing apparatuses may use various ink ejecting methods, including a piezoelectric method and an electrohydrodynamic method. In the piezoelectric method, ink droplets are ejected by deformation of a piezoelectric material. In the electrohydrodynamic method, ink droplets are ejected by an electrohydrodynamic force. Because an inkjet printing apparatus using the piezoelectric method may eject ink droplets in a drop on demand (DOD) manner, it is relatively easy to control the printing operation. In addition, because an inkjet printing apparatus using the electrohydrodynamic method forms minute droplets of ink with relative ease, an inkjet printing apparatus using the electrohydrodynamic method may facilitate precision printing.